Skip to content
Grain Farmers of Ontario is the province’s largest commodity organization,
representing Ontario’s 28,000 barley, corn, oat, soybean and wheat farmers.
Search
Ontario Grain Farmer Magazine

Determining the effectiveness of legume-based cover crops on nitrogen benefits to a subsequent corn crop

Principal Investigator: Kim Schneider

Research Institution: University of Guelph

Timeline: April 2022 – March 2025  

Objectives:

  • To assess the ability of annual legume-based cover crops planted following winter wheat harvest to provide a nitrogen credit to a subsequent corn crop in comparison with frost-seeded red clover. This will be evaluated as a monoculture and mixed-species cover crop and compared with a frost-seeded red clover cover crop under both twin row and conventional row planting. A cost of production analysis will be included.
  • To evaluate the effect of aboveground biomass removal of the cover crop on N benefits to the subsequent corn crop and assess the forage potential (including economic value) of these harvested cover crops.
  • To quantify the effect of concentrating legumes in bio-strips on N credit to the subsequent corn crop.

Impacts:

  • We will provide information about how altering winter wheat row spacing affects the uniformity of a red clover stand, which may enable a more reliable N credit to the subsequent corn crop.
  • New information on the potential of annual clovers (Berseem and Balansa) that are available on the Ontario market will be provided, which may provide options for farmers to use an annual legume to obtain N credits for corn.
  • Producers will gain knowledge on the value of different legume cover crops and legume-based cover crop mixtures as fall forage, allowing them to use cover crops as a dual-purpose crop.
  • The impact of removing the aboveground biomass of the cover crop on any benefits to the next year’s corn crop will be determined. This will identify whether it is worth it economically to harvest the cover crop as forage.
  • The testing of the effect of planting legume and radish cover crops in biostrips on the next year’s corn crop (yield and N credit) will enable producers to make an informed choice as to how to best plant their cover crop (uniformly across the field or in biostrips).

Scientific Summary:

In southwestern Ontario, there is an opportunity to reduce the use of N fertilizer applied to corn through the use of preceding legume-based cover crops. Red clover that is frost-seeded in the spring into a standing winter wheat crop has demonstrated significant benefits to a subsequent corn crop in terms of providing an N credit. However, red clover stands frequently suffer from non-uniformity across a field, which has reduced the uptake of using red clover by farmers. Annual cover crops planted after winter wheat harvest, specifically those that include legumes, have the potential to be an alternative to red clover and provide an N credit to the following crop.  Finally, if cover crops can be grown with the potential for harvest as forage, more farmers may be likely to adopt cover crop use. However, how the removal of aboveground cover crop biomass impacts any benefits to the subsequent crop remains to be determined.

In the proposed researched, we will provide information about how altering winter wheat row spacing affects the uniformity of a red clover stand. In addition, annual legume-based cover crops (in monocultures and in oat and radish mixtures) including Berseem clover, Balansa clover and Austrian winter pea will be compared with red clover in terms of being able to deliver a nitrogen credit to a subsequent corn crop. By collecting yield and forage quality data of cover crops over three years, the potential of using a cover crop for fall forage will be assessed.  Finally, we will also compare whether the placement of the legume and radish as a biostrip can improve any benefits to the next year’s corn crop. 

External Funding Partners:

The project was funded in part by the Ontario Agri-Food Innovation Alliance, a collaboration between the government of Ontario and the University of Guelph.

OMAFRA HQP Scholarship Program: Funded by the Ontario Agri-Food Alliance and the University of Guelph’s Food from Thought research program, The Highly Qualified Personnel Scholarship (HQP) program supports the development of skilled graduates who can meet the changing demands of the agri-food and rural sector.